Mops of the type having various swab-wringing mechanisms are well known and have been the subject of numerous improvements over the years. One particularly common and popular form is the self-wringing mop. As taught by Hertzberg, U.S. Pat. No. 1,760,695, this type of mop consists of a swab comprising multiple strands of material fixed at opposing ends to both the distal end of a mop handle and a sleeve rotatably and slidably disposed on the mop handle. By extending the sleeve longitudinally towards the distal end of the mop handle, the swab functions in its normal fashion for mopping. Conversely, retracting the sleeve stretches the swab so that it may be wrung by rotating the sleeve about the longitudinal axis of the handle.
It is also known in self-wringing mops of the type described that the swab may be detachably connected to the handle in such a way as to permit the use of different swabs. In this manner, used or worn out swabs may also be replaced. For example, Heinonen, U.S. Pat. No. 4,479,278, teaches a swab having multiple strands sandwiched at one end between the threadingly-engageable portions of a fixing head, which portions comprise a cup-like seat and a locking body. At their opposite ends the multiple strands of the swab are gathered by a tie to define a circular opening. A mop handle having distal and proximal ends includes a sleeve slidingly and rotatably disposed thereon, the sleeve flaring outwardly toward the distal end of the mop handle to define a hemispherical portion over which the circular opening of the swab is engaged. The hemispherical portion defines a greater diameter than the swab's circular opening, such that the swab will not disengage the sleeve during use.
Unfortunately, self-wringing mops of this type are unnecessarily complex. In order to change swabs in the Heinonen device, for example, a user has to separate the locking body from the remainder of the fixing head and extricate the swab from the cup-like seat. Subsequently, the swab must also be removed from the sleeve. This presents two problems. First, the locking body may be misplaced or inadvertently broken when it is separated from the fixing head, rendering the mop useless. Second, a user must contact the dirtiest portion of a used or worn-out swab--the area adjacent the locking body--in order to remove the swab and put a new one in its place.
Still another problem common to self-wringing mops is the tendency of the sleeve to freely slide towards the distal end of the mop handle, particularly under the weight of a swab soaked with water, cleaning solution, or other liquid. Consequently, such prior art mops cannot be hung vertically with the swab fully stretched for drying.
One solution to this latter problem has been to include a locking element disposed in fixed position on the mop handle proximate the upper end of the sleeve. When the sleeve is fully retracted, this locking element is threadingly engaged with a correspondingly threaded portion provided on the upper end of the sleeve. With the locking element and the sleeve so engaged, the sleeve resists sliding along the handle.
While effective in retaining the sleeve in a fixed position when the mop is vertically oriented, the above solution increases both the cost of manufacture of the mop, as well as its complexity of use.
A second solution to this problem has been to provide a friction cap to the upper end of the sleeve. The cap fits over the mop handle and comprises a short cylindrical tube having upper and lower openings and means for connecting to the upper end of the sleeve in a coaxial, overlapping relationship. The interior of the cap includes a plurality of flanges radiating inwardly downward from the upper opening of the cap. By virtue of the manner in which they limit the interior diameter of the friction cap, the flanges resist movement of the sleeve and friction cap along the mop handle.
Due to the type of connection between the friction cap and the sleeve, however, it is common for the sleeve to pull away from the friction cap under the weight of the swab.